This invention relates to a semiconductor device having a wiring layer or electrode made of polycrystalline silicon and metal silicide thereon and method of manufacturing the semiconductor device.
Recently, for reducing the electrical resistance of polycrystalline silicon gate electrodes or polycrystalline silicon wiring layers formed on a semiconductor substrate or source and drain regions or diffused wiring layers formed in a major surface of a semiconductor substrate of single crystal silicon as low as possible, it has frequently been practiced to form a metal silicide film on the upper surface of these electrodes, layers, or regions. The metal silicide film is formed, for example, by vapor-depositing a refractory metal having a high melting point such as molybdenum, tungsten, titanium, tantalum, etc., or platinum on the polycrystalline silicon or single crystal silicon and applying thereto a heat treatment to cause a thermal reaction of the metal and silicon. However, in the foregoing conventional technique, there is an anxiety of causing short-circuiting between the silicide film on the polycrystalline silicon formed on a semiconductor substrate and impurity regions such as source and drain regions in the semiconductor substrate.